Un matériau qui se répare tout seul. Une fissure ou une rayure qui se rebouche elle-même après un impact, comme une blessure pour un être vivant. Le concept d’autoréparation ainsi décrit n’est plus une idée purement fantaisiste issue de l’imagination fertile des chercheurs. De récents travaux prouvent le contraire. Catalyse a choisi de mettre au point un processus d’autoréparation par l’intégration de microparticules contenant un principe actif liquide, libéré lors son l’éclatement. Ce liquide, un monomère, va alors polymériser, rebouchant ainsi la fissure et empêchant sa propagation.L’innovation de Catalyse a été d’imaginer une formulation autoréparante capable de polymériser directement au contact du milieu extérieur. Les éléments alors mis à disposition par l’environnement peuvent être la lumière (rayonnements UV ou visibles), l’oxygène, ou l’humidité. Les monomères envisagés pour l’encapsulation sont alors respectivement un acrylate, TMPTA, ou une époxy (mélangés avec un photoamorceur adapté), l’huile de lin (siccative) et un isocyanate trimère de l’hexamétylène diisocyanate. L’encapsulation des ces quatre composés est étudiée en parallèle et les travaux réalisés sont explicités dans les chapitres 2, 3 et 4 de ce document. Le TMPTA et l’huile de lin sont encapsulés par le procédé sol-gel, l’époxy et l’isocyanate, par polycondensation interfaciale. Les résultats obtenus sont variables d’un monomère à l’autre, mais dans l’ensemble, les résultats sont concluants et montrent d’une part, qu’il est possible d’obtenir des particules contenant un taux de principe actif intéressant et stables dans le temps, et d’autre part que suite à l’éclatement desdites capsules, le monomère polymérise, assurant ainsi le processus d’autoréparation. / A material that could repair itself, a crack that can heal itself after an impact, like a wound on the body. The concept of self-healing described is not science fiction created by the crazy imagination of researchers. Recent studies show otherwise. The French company CATALYSE has developed a process of self-healing through the integration of microparticles containing an active liquid ingredient that is released during a crack in the material. The liquid monomer fills the crack, polymerizes and prevents further spread. The innovation of CATALYSE was to imagine a self-repairing formula, which polymerizes when exposed to the outside of the self-contained environment. This includes light (UV or visible rays), oxygen or humidity. The corresponding monomers to be encapsulated are respectively an acrylate (for example TMPTA), an epoxy (mixed with an adapted photoinitiator), linseed oil or diisocyanate (for example an isocyanine trimer or hexamethylene diisocyanate). The encapsulations of these four compounds were studied in parallel and the results are explained in chapters 2, 3 and 4 of this document. The TMPTA and linseed oil are both encapsulated by the sol-gel process, the epoxy and isocyanate, by interfacial polycondensation. The results vary from one monomer to another but the overall results are conclusive. They show that it is possible to obtain a high percentage of the active ingredient and that the particles stay stable over time. Following the bursting of such capsules, the monomer polymerizes and ensures the self-healing process.

Compostos orgânicos podem ser liberados dos materiais resinosos, mesmo após sua polimerização, como resultado da presença de monômeros residuais e do processo de degradação do próprio material, podendo ocasionar efeitos citotóxicos, genotóxicos e alergênicos. O objetivo do presente estudo, in vitro, foi avaliar a liberação de compostos orgânicos de dois materiais resinosos, recentemente lançados no mercado, que apresentam inovações em suas formulações (resinas Kalore TM - GC FUJI e FiltekTM Silorane - 3M ESPE), variando a fonte de luz polimerizadora (halógena ou LED), a solução de imersão (água ou saliva artificial) e o pH da solução de imersão (7 ou 4,5). Foram confeccionados 56 corpos de prova da resina Kalore TM e 56 da resina FiltekTM Silorane, sendo 28 polimerizados com luz halógena e 28 com luz LED. Após aleatorização, 7 corpos de prova de cada resina foram armazenados em água com pH neutro, 7 em água com pH ácido, 7 em saliva com pH neutro e 7 em saliva com pH ácido. A leitura dos espectros das soluções foi realizada por meio da espectroscopia de fluorescência após 1, 3, 24, 48, 72, 168, 216, 312, 432, 504 e 672 horas. Após 672 horas, ainda verificou-se a liberação de compostos orgânicos das resinas KaloreTM e FiltekTM Silorane em todas as condições avaliadas. A liberação de compostos orgânicos foi menor nos grupos experimentais polimerizados pela luz LED. A quantidade de compostos orgânicos liberados foi menor nas amostras imersas em saliva. A resina KaloreTM liberou uma quantidade maior de compostos orgânicos em pH neutro, independente do meio de imersão. A resina FiltekTMSilorane liberou uma quantidade maior de compostos orgânicos em pH ácido, quando imersas em água, e uma maior quantidade de compostos orgânicos em pH neutro, quando imersas em saliva. A resina FiltekTMSilorane liberou mais de um componente orgânico. A espectrometria de fluorescência permitiu avaliar a liberação de compostos orgânicos das resinas KaloreTM e FiltekTM Silorane. / Organic compounds may be released from the resin materials, even after polymerization, as a result of the presence of residual monomers and degradation of the material itself, which may cause cytotoxic, genotoxic and allergenics effects. The purpose of this study, in vitro, was to evaluate the release of organic compounds from two resin materials, recently launched on the market, that present innovations in their formulations (resins KaloreTM - GC FUJI and FiltekTM Silorane - 3M ESPE), varying the source curing light (LED or halogen), the immersion solution (water or artificial saliva) and the pH of the immersion solution (7 or 4.5). Were prepared 56 specimens resin KaloreTM and 56 resin FiltekTM Silorane, 28 polymerized with halogen light and 28 with LED light. After randomization, 7 samples of each resin were immersed in water at neutral pH, 7 in water at acid pH, 7 in the saliva at a neutral pH, and 7 in the saliva at acid pH. The reading of the spectra of the solutions was performed by fluorescence spectroscopy at 1, 3, 24, 48, 72, 168, 216, 312, 432, 504 and 672 hours. After 672 hours, there was still release of organic resins KaloreTM and FiltekTM Silorane under all conditions evaluated. The release of organic compounds was lower in the experimental groups polymerized by LED light. The amount of organic compounds released was lower in samples immersed in saliva. The resin KaloreTM released more organic compounds at neutral pH in both immersion media. The resin FiltekTMSilorane immersed in water released more organic compounds at acid pH, but when the resin was immersed in saliva the release of organic compounds was higher at neutral pH. The resin FiltekTMSilorane released more that one organic component. The fluorescence spectrometry allowed us to evaluate the release of organic compounds resins KaloreTM and FiltekTMSilorane.

Polyesters have been realised as a viable replacement for slow or non-degrading petroleum derived polymers. A variety of aliphatic polyesters, e.g. poly(lactic acid), have received a lot of attention because they are produced from renewable feedstocks and have the ability to biodegrade and bioassimilate. Poly(lactic acid)'s broader family, poly(α-hydroxy acid)s, have been produced with a wide variety of properties, that has given polyesters the potential for a more diverse range of applications. However, their synthesis has proven difficult. This thesis investigates a family of 1,3-dioxolan-4-ones as a monomer source to ease difficulties in current synthetic routes. Polymerisation of the parent 1,3-dixoxolan-4-one was tested. The copolymerisation of Llactide and 1,3-dioxolan-4-one was conducted with various monomer feedstocks. Ringopening polymerisation of 1,3-dioxolan-4-one led to the formation of paraformaldehyde as a polymerisation by-product. The copolymerisation was found to be best controlled when using a coordination-insertion type catalyst. 1,3-dioxolan-4-one was also copolymerised with ε-caprolactone and β-butyrolactone to produce copolymers with various compositions. The formation of poly(lactic acid) and poly(mandelic acid) from 5-methyl-1,3-dioxolan- 4-one and 5-phenyl-1,3-dioxolan-4-one was investigated. Poly(lactic acid) and poly(mandelic acid) were synthesised with either isotactic or atactic tacticities. Molecular weights were found to be lower than the expected values. A variety of MeAl(salen) catalysts were explored for the polymerisation of 5-methyl-1,3-dioxolan-4-one and catalysts ligated with tertiary-butyl substituted salens were found to have higher rates of polymerisation and reached high conversions. Altering the diimine bridge in the ligand led to variations in rates of polymerisation and molecular weights. The cause of the decrease in molecular weight was found to be caused by a side reaction. The side reaction was bypassed by polymerising 2,2,5- trimethyl-1,3-dioxolan-4-one and 2,2-dimethyl-5-phenyl-1,3-dioxolan-4-one to form poly(lactic acid) and poly(mandelic acid), respectively, with the expulsion of acetone. The scope of 1,3-dioxolan-4-ones capable of being polymerised to form poly(α-hydroxy acid)s was expanded to include iso-propyl, cyclohexyl, normal-butyl, iso-butyl, propargyl, chloromethyl and benzyloxymethyl substituents at the five position. The glass transition temperatures accessible from this synthetic route was expanded (22-105 °C). Kinetic experiments revealed the impact of the substituents steric bulk on the rate of polymerisation and points toward a coordination-insertion mechanism. Poly(lactic acid-co-glycolic acid) was copolymerised with 5-propargyl-1,3-dioxolan-4-one to incorporate alkynyl functionality and hence Raman spectroscopy showed the polymer had a distinct peak at 2128 cm-1. Following post-polymerisation modification of poly(lactic acid-co-3-chloro-2-hydroxypropanoic acid) copolymers, acrylate functionalised polymers were produced. The copolymers were shown to be capable of crosslinking poly(α-hydroxy acid) and poly(methyl methacrylate).

Banca: Maria Auxiliadora Junho de Araujo / Banca: Marco Antonio Bottino / Banca: Antonio Muench / Banca: Simonides Consani / Banca: Zlata Victorovna Hvanov / Resumo: No presente trabalho objetivou-se estudar o desempenho de 4 ciclos de polimerização das RAAT: ciclo I - 65°C por 30 min, 50°C por 23h e 30min e 100°C por 1 h; ciclo II - 50°C por 24h e 1 h a 65°C, 30 min para elevar a 100°C e 1 h a 1 00°C, com outros dois, rotineiramente indicados: ciclo III - 9h a 72°C e o ciclo IV - 1 h a 65°C, 30 min para elevar a 100°C e 1 h a 100°C. As observações, para que pudesse ser analisado o desempenho, foram: verificação do monômero residual, alterações de peso e dimensional linear, porosidade e dureza. Os resultados apontaram quanto ao monômero residual, diferenças significantes estatisticamente no fator ciclo; na alteração de peso, o fator armazenagem e a interação entre os fatores ciclo X armazenagem mostraram diferenças estatisticamente significantes; quanto a alteração dimensional linear, diferenças significantes estatisticamente foram observadas para o fator armazenagem; para a dureza não foram verificadas diferenças significantes e as porosidades não foram observadas nos ciclos I e II, no ciclo III em grau mínimo e em quantidade apreciável no ciclo IV / Abstract: In the present work it was studied the behavior of four water bath curing cycles of heat activated acrylic resin considered as long duration (I - 65ºC for 30 min;50ºC for 23h and 30min; and 100º C for 1h; II- 50ºC for 24h and the rapid cycle), compared to the known long time curing cycle (9 hours for 72ºC) and short curing cycle (1 h for 65ºC; 30 min to elevate at 100º C and 1:00 to 100º C). Analysis consisted of observations and verification of the residual monomer, weight alterations, dimensional, dimensional lineal, porosity and hardness to determine material performance. The results pointed out that residual monomer presented statistical significant differences in the factor storage and interaction among the factors cycle X storage for weight alteration; statistical significant differences for the factor storage for lineal dimensional alterations, without significant differences for hardness. Porosity was verified in minimum degree in the cycle III and in appreciable amount in the cycle IV

Thesis (Ph. D.)--University of Chicago, Department of Physics, December 2003. / Includes bibliographical references. Also available on the Internet.

Plastic debris are accumulating in our oceans and are degraded into smaller pieces which eventually becomes small enough to be available to lower thropic level organisms. Microplastics, commonly defined as plastic particles <5 mm, are globally distributed and found at remote locations far away from industrialized and populated areas. The effects of macro sized plastics is well understood whilst the effects of microplastics is hard to predict. It is known that microplastics act as transfer vectors for a wide range of toxic chemicals into organisms, and it is also known that the particle itself can cause toxic responses such as increased immune response and endocrine disruption. Researchers utilize virgin plastic pellets in order to determine the toxicological effect of the plastic particle itself, but resent research suggest that these virgin plastics may release chemicals that contribute to the toxic response and thus complicates the interpretation of the results. In present study, five different virgin plastics were allowed to leach in artificial seawater under conditions that mimic those used in particle toxicity studies. Plastics included were polyethylene, polypropylene, polyvinyl chloride, high-density polyethylene and polystyrene. Leachable monomers and oligomers were found in three of the five plastics tested: polyvinyl chloride, high-density polyethylene and polystyrene. Leached compounds from polyvinyl chloride were not identified due to time limitations. Aliphatic hydrocarbons in the size C14-C22 were leached out from high-density polyethylene in the concentration range 0.47 × 10-3 – 1.13 × 10-3 μg ml-1 within 24 hours. Polystyrene was found to leach styrene monomer which reached a concentration of 0.17 μg ml-1 within 24 hours.

No description available.

We have synthesized norbornene-functionalized side-chain monomers for potential use as hole transporting and electron transporting/hole blocking materials in organic light-emitting diodes. TPD-norbornenes were prepared. The monomers demonstrated similar electrochemical and absorbance spectra to the parent TPD small molecule. The similarity is promising for using the monomers in OLEDs because TPD is a known blue-emitter with relatively high hole mobility in amorphous thin films. 1,10-Phenanthroline small molecules and monomers were synthesized to explore their potential as hole blocking materials in multilayer devices. We had difficulty purifying the monomers; however, the small molecules were slightly easier to reduce than commonly used hole blocking materials 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline.

Thesis (Ph.D.) - Carleton University, 2006. / Includes bibliographical references (p. 151-159). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 158-166). Also available on the Internet.